import 'package:get/get.dart';
import 'package:flutter/material.dart';
import 'package:get_storage/get_storage.dart';
import 'dart:convert';
import '../../../data/services/volcano_ai_service.dart';
import '../../../data/services/volcano_tts_service.dart';
import '../models/message_model.dart';

class ChatController extends GetxController {
  late final String agentId;
  late final String agentName;
  late final String agentAvatar;
  late final String? agentSubtitle;
  late final String systemPrompt;
  late final String welcomeMessage;
  late final bool playVoiceOnEnter;
  final VolcanoAIService _aiService = VolcanoAIService();
  late final VolcanoTtsService _ttsService;
  static const String _storagePrefix = 'chat_history_';

  final messages = <Message>[].obs;
  final isLoading = false.obs;
  late final TextEditingController textController;
  late final ScrollController scrollController;
  final _storage = GetStorage();

  // 用于存储当前正在流式生成的消息
  final RxString currentStreamMessage = ''.obs;
  Message? _currentAssistantMessage;
  String _pendingTtsText = ''; // 用于累积TTS文本
  static const int _minTtsLength = 20; // TTS最小文本长度
  bool _isDisposed = false; // 添加销毁标记

  ChatController() {
    _initControllers();
    _initTtsService();
    _initFromArguments();
  }

  void _initFromArguments() {
    final arguments = Get.arguments as Map<String, dynamic>;
    agentId = arguments['agentId'] as String;
    agentName = arguments['agentName'] as String;
    agentAvatar = arguments['agentAvatar'] as String;
    agentSubtitle = arguments['agentSubtitle'] as String?;
    systemPrompt = arguments['systemPrompt'] as String;
    welcomeMessage = arguments['welcomeMessage'] as String;
    playVoiceOnEnter = arguments['playVoiceOnEnter'] as bool? ?? false;
  }

  void _initControllers() {
    textController = TextEditingController();
    scrollController = ScrollController();
  }

  void _initTtsService() {
    try {
      _ttsService = Get.find<VolcanoTtsService>();
    } catch (_) {
      _ttsService = Get.put(VolcanoTtsService(), permanent: true);
    }
    _ttsService.isEnabled.value = true;
  }

  @override
  void onInit() async {
    super.onInit();
    await _initializeController();
    
    // 如果需要在进入时播放语音，延迟一下以确保页面已加载
    if (playVoiceOnEnter) {
      Future.delayed(const Duration(milliseconds: 500), () {
        generateSimpleGreeting();
      });
    }
  }

  Future<void> _initializeController() async {
    try {
      await _loadChatHistory();

      await _showWelcomeMessages();
    } catch (e) {
      Get.snackbar(
        'Error',
        'Failed to initialize chat: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  Future<void> _showWelcomeMessages() async {
    try {
      if (messages.isEmpty && agentName.isNotEmpty) {
        // 生成动态问候语
        await _generatePersonalizedGreeting();
      }
      // 保存聊天记录并滚动到底部
      await _saveChatHistory();
      Future.delayed(const Duration(milliseconds: 100), _scrollToBottom);
    } catch (e) {
      print('显示欢迎消息失败: $e');
      // 如果生成问候语失败，确保至少显示静态欢迎消息
      if (_ttsService.isEnabled.value) {
        _ttsService.speak(welcomeMessage);
      }
    }
  }

  Future<void> _generatePersonalizedGreeting() async {
    if (_isDisposed) return;

    String fullGreeting = '';
    try {
      currentStreamMessage.value = '';
      _currentAssistantMessage = Message(
        role: 'assistant',
        content: '',
        timestamp: DateTime.now(),
      );
      messages.add(_currentAssistantMessage!);

      // 构建用于生成个性化问候语的消息列表
      final greetingMessages = [
        {'role': 'system', 'content': systemPrompt},
        {
          'role': 'user',
          'content': '请根据你的身份和性格，用一句简短的话向我打个招呼，要体现你的特点，不要超过18个字。'
        },
      ];

      await for (final chunk in _aiService.sendMessageStream(
        messages: greetingMessages,
        systemPrompt: systemPrompt,
      )) {
        if (_isDisposed) break;

        // 更新消息内容
        currentStreamMessage.value += chunk;
        _updateAssistantMessage(currentStreamMessage.value);
        fullGreeting += chunk;
      }

      // 完整问候语生成完毕后，一次性播放
      if (!_isDisposed &&
          _ttsService.isEnabled.value &&
          fullGreeting.isNotEmpty) {
        await _ttsService.speak(fullGreeting);
      }
    } catch (e) {
      print('生成问候语失败: $e');
      // 移除未完成的消息
      if (_currentAssistantMessage != null) {
        messages.remove(_currentAssistantMessage);
      }
    } finally {
      if (!_isDisposed) {
        _currentAssistantMessage = null;
        currentStreamMessage.value = '';
      }
    }
  }

  @override
  void onClose() {
    _cleanupResources();
    super.onClose();
  }


  @override
  void dispose() {
    _cleanupResources();
    super.dispose();
  }

  void _cleanupResources() {
    if (_isDisposed) return; // 防止重复清理
    _isDisposed = true;

    try {
      if (textController.hasListeners) {
        textController.dispose();
      }
    } catch (e) {
      print('Disposing textController failed: $e');
    }

    try {
      if (scrollController.hasClients) {
        scrollController.dispose();
      }
    } catch (e) {
      print('Disposing scrollController failed: $e');
    }

    try {
      _ttsService.stop();
    } catch (e) {
      print('Stopping TTS service failed: $e');
    }

    // 清理其他资源
    currentStreamMessage.value = '';
    _currentAssistantMessage = null;
    _pendingTtsText = '';
  }

  Future<void> _loadChatHistory() async {
    try {
      final historyJson = _storage.read('${_storagePrefix}${agentId}');
      if (historyJson != null) {
        final List<dynamic> historyList = json.decode(historyJson);
        messages.value =
            historyList.map((item) => Message.fromJson(item)).toList();
      }
    } catch (e) {
      Get.snackbar(
        'Error',
        'Failed to load chat history: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  Future<void> _saveChatHistory() async {
    try {
      final historyJson =
          json.encode(messages.map((msg) => msg!.toJson()).toList());
      await _storage.write('${_storagePrefix}${agentId}', historyJson);
    } catch (e) {
      Get.snackbar(
        'Error',
        'Failed to save chat history: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  void _scrollToBottom() {
    if (scrollController.hasClients) {
      scrollController.animateTo(
        scrollController.position.maxScrollExtent,
        duration: const Duration(milliseconds: 300),
        curve: Curves.easeOut,
      );
    }
  }

  void _updateAssistantMessage(String content) {
    if (_currentAssistantMessage != null) {
      final index = messages.indexWhere((msg) =>
          msg.timestamp == _currentAssistantMessage?.timestamp &&
          msg.role == _currentAssistantMessage?.role);

      if (index != -1) {
        messages[index] = Message(
          role: 'assistant',
          content: content,
          timestamp: _currentAssistantMessage!.timestamp,
        );
        _scrollToBottom();
      }
    }
  }

  void sendMessage(String text) async {
    if (text.trim().isEmpty) return;

    final userMessage = Message(
      role: 'user',
      content: text,
      timestamp: DateTime.now(),
    );
    messages.add(userMessage);
    textController.clear();
    await _saveChatHistory();
    _scrollToBottom();

    isLoading.value = true;
    try {
      currentStreamMessage.value = '';
      _currentAssistantMessage = Message(
        role: 'assistant',
        content: '',
        timestamp: DateTime.now(),
      );
      messages.add(_currentAssistantMessage!);
      _pendingTtsText = '';

      await for (final chunk in _aiService.sendMessageStream(
        messages: messages
            .map((m) => {
                  'role': m.role,
                  'content': m.content,
                })
            .toList(),
        systemPrompt: systemPrompt,
      )) {
        if (_isDisposed) break;

        currentStreamMessage.value += chunk;
        _updateAssistantMessage(currentStreamMessage.value);

        // 累积文本并合成
        _pendingTtsText += chunk;
        if (!_isDisposed && _ttsService.isEnabled.value) {
          // 检查是否达到最小长度
          if (_pendingTtsText.length >= _minTtsLength) {
            // 找到最后一个句子结束的位置
            int lastSentenceEnd = _findLastSentenceEnd(_pendingTtsText);
            if (lastSentenceEnd > 0) {
              // 播放到最后一个句子结束的位置
              String textToSpeak =
                  _pendingTtsText.substring(0, lastSentenceEnd + 1);
              _ttsService.speak(textToSpeak);
              // 保留剩余的文本
              _pendingTtsText = _pendingTtsText.substring(lastSentenceEnd + 1);
            }
          }
        }
      }

      // 处理剩余的文本
      if (!_isDisposed &&
          _ttsService.isEnabled.value &&
          _pendingTtsText.isNotEmpty) {
        _ttsService.speak(_pendingTtsText);
      }
      _pendingTtsText = '';

      if (!_isDisposed) {
        await _saveChatHistory();
      }
    } catch (e) {
      if (!_isDisposed) {
        if (_currentAssistantMessage != null) {
          messages.remove(_currentAssistantMessage);
        }
        Get.snackbar(
          'Error',
          'Failed to get response from AI: $e',
          snackPosition: SnackPosition.BOTTOM,
        );
      }
    } finally {
      if (!_isDisposed) {
        _currentAssistantMessage = null;
        currentStreamMessage.value = '';
        isLoading.value = false;
      }
    }
  }

  int _findLastSentenceEnd(String text) {
    final sentenceEnds = [
      text.lastIndexOf('。'),
      text.lastIndexOf('！'),
      text.lastIndexOf('？'),
      text.lastIndexOf('.'),
      text.lastIndexOf('!'),
      text.lastIndexOf('?'),
    ];

    return sentenceEnds.reduce((max, pos) => pos > max ? pos : max);
  }

  Future<void> clearChat() async {
    try {
      messages.clear();
      await _storage.remove('${_storagePrefix}${agentId}');
      await _showWelcomeMessages();
    } catch (e) {
      Get.snackbar(
        'Error',
        'Failed to clear chat: $e',
        snackPosition: SnackPosition.BOTTOM,
      );
    }
  }

  void toggleTTS() {
    _ttsService.toggleEnabled();
  }

  /// 生成简单的问候语
  Future<void> generateSimpleGreeting() async {
    try {
      currentStreamMessage.value = '';
      _currentAssistantMessage = Message(
        role: 'assistant',
        content: '',
        timestamp: DateTime.now(),
      );
      messages.add(_currentAssistantMessage!);

      // 构建用于生成问候语的消息列表
      final greetingMessages = [
        {'role': 'system', 'content': systemPrompt},
        {'role': 'user', 'content': '请用一句简短的话向我打个招呼，要体现你的特点，不要超过12个字。'},
      ];

      String fullGreeting = '';
      await for (final chunk in _aiService.sendMessageStream(
        messages: greetingMessages,
        systemPrompt: systemPrompt,
      )) {
        if (_isDisposed) break;

        // 更新消息内容
        currentStreamMessage.value += chunk;
        _updateAssistantMessage(currentStreamMessage.value);
        fullGreeting += chunk;
      }

      // 完整问候语生成完毕后，一次性播放
      if (!_isDisposed && _ttsService.isEnabled.value && fullGreeting.isNotEmpty) {
        await _ttsService.speak(fullGreeting);
      }
    } catch (e) {
      print('生成问候语失败: $e');
      // 移除未完成的消息
      if (_currentAssistantMessage != null) {
        messages.remove(_currentAssistantMessage);
      }
    } finally {
      if (!_isDisposed) {
        _currentAssistantMessage = null;
        currentStreamMessage.value = '';
      }
    }
  }

}